Fix 345521: "return 0" in handler cancels events, r/sr=bz

dom/src/events/nsJSEventListener.cpp

@@ -243,13 +243,7 @@ nsJSEventListener::HandleEvent(nsIDOMEvent* aEvent)
           vrv->GetAsDOMString(beforeUnload->text);
         }
       }
-    } else if (dataType == nsIDataType::VTYPE_BOOL ||
-               dataType == nsIDataType::VTYPE_INT8 ||
-               dataType == nsIDataType::VTYPE_INT16 ||
-               dataType == nsIDataType::VTYPE_INT32 ||
-               dataType == nsIDataType::VTYPE_UINT8 ||
-               dataType == nsIDataType::VTYPE_UINT16 ||
-               dataType == nsIDataType::VTYPE_UINT32) {
+    } else if (dataType == nsIDataType::VTYPE_BOOL) {
       // If the handler returned false and its sense is not reversed,
       // or the handler returned true and its sense is reversed from
       // the usual (false means cancel), then prevent default.

dom/tests/html/jshandlers.html

@@ -3,6 +3,20 @@
 The link below has an onmousedown, an onmouseup, and an onmousemove handler.
 Mouseover or click for event info in debug console.
 <a href="jshandlers.html">Link back to this page</a>
+
+<p>The link below has an event that should open www.mozilla.org when 
+   clicked
+</p>
+<!-- The link does 'return 0' - as per bug 345521 this should *not* be 
+     interpreted as false
+-->
+<a href="http://www.mozilla.org" onclick="return 0">Click me</a>
+
+<p>The link below has an event that is cancelled - nothing should happen when 
+   clicked
+</p>
+<a href="http://www.mozilla.org" onclick="return false">Click me<a/>
+
 </body>
 <script>
 function findElementByTagName(start, tag)